U-Pb radioisotope dating is now the absolute dating method of first choice among geochronologists, especially using the mineral zircon.A variety of analytical instruments have also now been developed using different micro-sampling techniques coupled with mass spectrometers, thus enabling wide usage of U-Pb radioisotope dating.Uranium minerals themselves are too uncommon to be very useful in dating.
These ages are often confirmed by Rb-Sr, Lu-Hf, Re-Os, and Sm-Nd isochron ages, but agreement could be due to calibration with the Pb-Pb system. “The Interpretation of Lead Isotopes and Their Geological Significance.” In Radiometric Dating for Geologists.
However, problems remain in the interpretation of the measured Pb isotopic ratios to transform them into ages.
Among them is the presence of non-radiogenic Pb of unknown composition, often referred to as common or initial Pb.
Zircon is especially useful because it frequently contains uranium in substitution for zirconium, but does not incorporate lead (as shown by the absence of Lead-204).
Thus all the lead in the zircon can be assumed to be radiogenic.